Hey guys I have interesting idea and was wondering if anyone has ever done it or has seen it done on a older truck. I have a 1978 F250 ranger 2wd and I want to convert it to 4wd. I know that most people that do this do a frame swap because of the difference of the coil spring frame to the leaf spring frame. And I'm not a fan of the ttb frontends. So my idea is to take the frontend out of the 6.0 powerstroke since it is a coil over spring frontend and a straight axle. I think by doing this I wouldn't have to deal with doing a frame swap as long as the frame widths are same from my 1978 to the 6.0?
Please let me know your opinion, Thanks

 

I suspect its a little more complex than this, judging by the fact that there are some amazingly talented fabricators who post here, and i dont recall hearing of this exact swap.........I also am guessing that a 6.0 will eat up a Dana 60 rear axle, which is what your 78 F250 should have.

 

Well funny thing you are asking this because I looked at doing this exact same thing.. Converting a 1973 F-350 SCS to 4wd. It can be done but I will tell you that to do it right you are going to need to either lift the truck substantially to allow the axle to clear the cross member or remove the cross member and build a custom one. The frame widths are quite a bit different also. The 2wd frame is like 31" center and the 6.0 frame is like 42" (iirc). Custom link bars would be necessary for the frame width difference and youd have to fab a trac bar as well.

Eventually I will do this swap but for now I went ahead and used pre-made leaf hangers from a local company and used factory 77.5-79 shackle hangers (frame mount) and factory shackles with 3" superduty leaf springs, cross over steering and custom trac bar. Everything turned out rather nice and axle placement was easy enough. I don't know that id want to do it any other way than having nothing forward of the bed on the chassis. The rivets aren't bad to remove with a grinder and torch and nice big ballpein hammer. it just getting everything apart that was welded from the factory.

If I was to do it all over again I would go the same route I went. Total cost was around $1300. Dana 44 axle $400, Parts to freshen axle $250, Cross over steering parts $250, Tie Rod Kit $150, Hanger $50, Hardware $90, and steering box F-150 $100.

Just a little insight, hope this helps.

 

Here is a little cut and past info for you.

There is nothing nuts and bolts about a 4wd conversion, there is not a thing that is bolt on or swappable.
The engine cross members are entirely different, and this means that if an un molested truck is what you are after, it will be impossible to create one with a 2wd platform. The 2wd will have to be lifted quite a way to clear the front diff. 2wd trucks are coil sprung and most F250 4wd's are leaf sprung. None of the suspension items are even close to the same, so you will be fabricating or modifying some original 4wd stuff to work.

Steering systems are entirely different as well, so you will be upgrading that too. My last conversion with leafs ran me several thousand dollars, and that was with the work that I performed for free.
The difference in sale values between a 4wd and 2wd are minimal, and the 4wd conversion is hardly justifiable. How far away are you looking? I pick up F250 4x4's for reasonable money. Consider the cost of shipping, and then consider buying a west coast truck with no rust, and I can guarantee that you will be time and money ahead.

Well the frames are similar, with a few exceptions. The frame horns are slightly different, and the frame widths aft of the cab ar different from 73 to 77 trucks. The frame rise is also slightly different, but this is not a show stopper and does not make much difference one the fabrication begins.
Not that the important question is whether or not you will be using a coils springs or a leaf spring. It is possible to install a 78/9 radius arm and suspension. Not a big deal really, and with a standard cab this is reasonable. Not quite as easy with a super cab and or crew cab.

The 2wd frames are not cut for the shackle pivot, and they do not have the provisions for a spring hanger, but again, this is not a deal breaker. Installing a pivot is just a tedious process. Accuracy is key, but I am not telling you anything that you do not already know.

Ok, so next is the transfer case. You have two choices, Install a married case, and this requires the proper transmission. Might find some difficulty making or modifying an output shaft to accommodate the early C6 and a married transfer case. So then the next option is to find a divorced transfer case, and install this. You will have to make up a cross member, but then you will have to get creative with the shifter linkage. See the 4wd trans will have an adapter or tailshaft with a pivot for a typical 205 shifter. Fabrication is the only limiting factor here.

Next and final factor will be the speedo. See your speedo works from the trans, so that being the case, you will have to get a speed reference form the t-case. If you do not, the speedo will read twice as fast when you put the case in low range.

As mentioned the steering box will have to be relocated, and the truck will require some lift. That engine crossmember has limited clearance so you will be looking at some lift to even clear it. The other option would be to remove it and replace it with a tubular unit.

This is a heck of a project. Not unreasonable, but a project none the less. 2500 bucks for a 2wd might get expensive. I paid 1300 bucks for a 4wd 75 last year, and it was already 4wd with 38" tires, and a strong 460, A/c, and plenty of goodies. I have made these conversions, and can tell you that it is a chore.